*{
    margin: 0;
    padding: 0;
}

div{
    background: #000;
    width: 400px;
    height: 400px;
    margin: 0 auto;
    span{
        background: red;
        width: 200px;
        height: 200px;
        display: inline-block;
        p{
            width: 100px;
            height: 100px;
            background: green;
            margin: 0 auto;
        }
    }
}